The Bone Center Microarray Core Facility will provide Bone Center investigators with high quality human, rat and mouse cDNA microarrays and technical expertise to broadly define and compare gene expression patterns. The Bone Center Microarray Core Facility will leverage significant support from the University of Michigan Microarray Network. The University of Michigan Microarray Network represents a commitment of greater than $2 million. This Network provides funds for equipment, acts as clearinghouse for technologic advancement, and purchases all commercially available sequence-verified human, rat and mouse clones; these clones will be duplicated and distributed to the Bone Center Microarray Core Facility free of charge. The Bone Center Microarray Core Facility will be housed in the existing Mental Health Research Institute/Department of Psychiatry (MHRI/Psych) Microarray Node. The Bone Center Microarray Core Facility will contribute one full time research assistant to the existing MHRI/Psych Microarray Node and will pay all costs associated with microarray production and analysis by Bone Center investigators. No support is being requested for equipment as all needed equipment is currently in place within the fully operational MHRI/Psych Microarray Node. The Bone Microarray Core Facility will be Co-Directed by Drs. Ignelzi and Thompson. Dr. Ignelzi, an experienced investigator in the bone field, will help Bone Center investigators design their experiments to fully utilize the potential of microarray technologies and he will assist investigators analyze their data. Dr. Thompson will run the Bone Center Microarray Core Facility on a day to day basis. Dr. Thompson has substantial microarray expertise and has established a fully functional microarray laboratory (MHRI/Psych Microarray Node) as well as the Central Node within the University of Michigan Microarray Network. In conjunction with the Bone Cell Molecular and Functional Analysis Core, the Bone Center Microarray Core Facility will provide a full range of microarray services to Bone Center investigators. This user-friendly core facility will advance scientific progress in many areas related to bone structure, maintenance and function.